1. Technical Field
The present invention relates to boron cage compound-containing compounds and composites for shielding and absorbing neutrons, and articles of manufacture incorporating the same.
2. Description of Related Art
Ionizing radiation is widely used in industry and in medicine. Radiation not only poses health concerns for living organisms, including increased risk of mutations, etc. upon exposure, but also creates issues for objects and materials used in industrial components exposed to such radiation, such as satellites, aircraft, and nuclear reactors. Electromagnetic interference is another problem encountered by such devices. Neutrons, in particular, have the ability to induce radioactivity over time in most substances they encounter. Neutrons also degrade materials and can lead to embrittlement of metals or swelling of other materials. For example, neutrons are known to affect the electronics, software, and hardware in airplanes and satellites. In particular, neutrons can affect silicon substrates used in memory devices, leading to device upsets which can lead to reprogramming of memories and CPUs, and ultimately malfunction of the device. In addition, aircraft personnel are exposed to significant radiation doses over time at commercial aircraft altitudes. There is a continuing need for improved materials for shielding and absorbing radiation, and protecting people, as well as industrial components from the harmful and deteriorating effects of such radiation.
Polymer composites and nanocomposites have been the subject of intense research in recent years. Through the successful incorporation of fillers, such as nanofillers and other nanostructures, polymer composites have demonstrated advanced material properties including reinforcement, thermal, flame, moisture, and chemical resistance, charge dissipation, barrier/gas transport properties, electrical conductivity and resistance, among others. Born cage compounds (“BCCs”) are icosahedral, closed cage molecules (e.g., carboranes (closo-C2B10H12 and dodecaborane anions) or boranes ([closo-B12H12]2−)). As molecular “nanoparticles,” BCCs can be incorporated into a variety of polymer networks as nanofillers in a number of ways to create new polymers, compositions, and composite materials for shielding and absorbing radiation. The synthesis, polymerization and copolymerization, and blending/compounding of BCCs in a variety of host polymer matrices and subsequent uses for shielding and absorbing radiation have not been systematically studied prior to this work.